With this insight, he quickly developed what later became known as the RSA encryption algorithm. [10][11]

GCHQ was not able to find a way to use the algorithm, and treated it as classified information. The scheme was also passed to the NSA.[9] With a military focus, and low computing power, the power of public-key cryptography was unrealised in both organisations:

I judged it most important for military use. In a fluid military situation you may meet unforeseen threats or opportunities. ... if you can share your key rapidly and electronically, you have a major advantage over your opponent. Only at the end of the evolution from Berners-Lee [in 1989] designing an open internet architecture for CERN, its adaptation and adoption for the Arpanet ... did public key cryptography realise its full potential. -Ralph Benjamin[9]

In 1977 the algorithm was independently invented and published by Rivest, Shamir, and Adleman, who named it after their initials. There is no evidence of a hint or leak, conscious or unconscious and Cocks has dismissed the idea.[9] The British achievement remained secret until 1997.[12]

In 1987, the GCHQ had plans to release the work, but Peter Wright's Spycatcher MI5 memoir caused them to delay revealing the research by ten years.[13] 24 years after its discovery, on 18 December 1997, Cocks revealed of the GCHQ history of public-key research in a public talk. James Ellis had died on 25 November 1997, a month before the public announcement was made.

Clifford Cocks is distinguished for his work in cryptography. He was the first to devise a practicable implementation of public key cryptography, and more recently a practicable scheme for identity based public key encryption. Such achievements have been fundamental in ensuring the security of the world's electronic communications, security that we now take for granted.[2]